Mechanical Engineering

{| |- | ASTM A572 DIN 1.0570 ST52 |}

A SYSTEM is any active device if left as open loop it will saturate one way or the other if the gain is ample. To control a system it must have some feedback to determine ts linear operating capabilities. As an example an airplane taking off at las Vegas the cabin will be pressurised to -1000 feet from the ground and maintain a rate of climb to even 50.000 feet with a delta of 17 PSI The cabin pressure as a system will maintain this delta by close loop control otherwise we will need oxygen if flying. INTERESTING?

Building a plane is a large undertaking that can take years to complete. It starts off with ideas. These ideas are pitched to airlines so the manufacture can get an idea of what kind of plane its customers want. Furthermore, extensive market analysis is done to predict whether the considered plane will be marketable by time the first prototype is developed, flown, tested, and certified. Once the manufacturing is satisfied that the plane is marketable and sufficient interest is present by the airlines, then initial development begins. The final dimensions, look and feel of the plane are hashed out by the designers. Once a rough idea is born, scaled models are built so they can be tested and the final design finalized.

It might be hard to believe, but the earliest airlines built by Boeing and other manufacturers, including the Boeing 747 where designed, and draw by hand on hundreds and thousands of individual blue prints. The Boeing 777 was one of the first airliners to be built in computers with programs such as CAD (Computer Aided Design). You can now begin to imagine how many years it takes before a full scaled model can even be built and flown. For example, the Airbus A380 idea was brought up back in the 1980's and it wasn't till the early 1990's that the project began and it wasn't till recent years that the plane was finally delivered and entered service!

Today, thanks to the help of computers a plane can be built faster, more accurately, and design problems worked out before the plane is even built. CAD can even tell the designers what parts are weak and make recommendations on how to make the part stronger. Parts can even be tested for their strength and durability in CAD. Back in the day a part had to be made, then tested and sent back to the factory to be redesigned, which cost a lot of money.

To find the Young's modulus of steel or any other material you require a plot of it's deformation response to loading. Specifically it's axial stress vs axial strain.

From this you need to find the gradient of the straight line portion of the curve where the material is behaving elastically and obeying Hooke's law. This is essentially stress / strain and gives you Young's modulus.

Reduced friction, smoother operation, more power delivered.

A big disadvantage is that the slot in the yoke wears rapidly due to sliding friction.

these are the load varrying uniformly from zero to a particular value and spread over a certain length of the beam.Such load is also called triangular load.The total load can be obtained by calculating the total area of triangle & multiplied if by the intensity or rate of loading.The total load will act through the centroid of the triangle.

Cooling Load is the amount of energy that is to be extracted from a house to develop a conditioned environment. There are two types of cooling loads i.e, sensible cooling load and latent cooling load....

Heating Load is the amount of heat that is to be supplied to a house in order to increase its temperature to maintain desired temperature...

There are wood pipes, glass pipes, and even marble pipes.

cast iron consists of 2% - 4% of carbon in it. cast iron is pig iron remelted and thereby refined together with definite amount of limestone,steel scrap, and spoiled castings.

it consists of small % of sulphur, silicon,phosphorus and manganese

wrought iron is highly refined iron with a small amount of slag forged out into fibres. it consists of 99% iron. it is almost the purest form of iron. it is highly ductile,rusts extremely quickly, it cannot be heat treated

what is equivalent to 65MN

Neither, that is a matter of opinion. Various people will give you various answers. If you look at numbers, at least near where I live, there are many more mechanical engineers than computer engineers, so you could say that mechanical engineering is more popular. But you cannot say which is better without more detail, in example: better salary, or better job opportunities.

Takes time. Che doesn't study software enginnering principles. However, he can easily learn technologies with his problem solving skills. I doubt a chemical engineer can create software technologies with his knowledge.

18 gauge stainless steel is 0.0500 inches thick.

Electrical generators work at about 11,000 volts which is not enough to transmit power over long distances over about 5 miles. Therefore step-up Transformers are used to connect them to the local grid on 132 kV or the supergrid on 275 or 400 kV (in the UK)

The only certain application of Bernoulli's Theorem I know is in the Bernoulli's Theorem experiment in college. All other examples are in my opinion a restatement of Newtons Laws, a missinterpretation of results or a failure to fully understand what is physically happening such as in the fallacy that lift in an aerofoil is due to BT. Bernoulli's Theorem is used by the Fire Brigade to calculate velocity and range of different types of fire-fighting equipment. Going hand-in-hand with the Venturi effect, it help to calculate reach and pressure required to obtain that reach during fire-fighting operations. Example: A pump supplies 6kW of energy to the water flowing thorugh a 45mm hose. If the water flows 25m vertically and through a 25mm branch at a rate of 480l/min, use Bernoulli's equation to find pressure at the branch.

*joint between the piston rod and and the crosshead of the steam engine

*joint between the slide spindle and the fork of the valve mechanism

*joint between the piston rod and the tail

Also called Norton's mechanism, is a method of changing feed rates.

You can find it on http://books.google.co.in/books?ei=OauuT-vvKdHQrQeO6rCYBA&id=_wWET38FZqsC&dq=machine+tool+design&q=meander#v=onepage&q&f=false

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A gib is a sacrificial piece that can be replaced once worn, allowing a joint to function correctly. e.g. Calipers have gibs (Copper strips) which allow the measuring head to tranverse the scale keeping the jaws parallel.

There is an old joke: "What's the difference between civil and mechanical engineers? Mechanical engineers build weapons -- civil engineers build targets." Yuck yuck. In reality civil engineering involves the design and construction of buildings, roadways, bridges, railroads, water supply, drainage, and sewers. Sometimes this is referred to as "infrastructure" Usually these are larger things that have a long service life. Mechanical engineering deals with machinery -- automobiles, trucks, machine tools, engines, pumps, and things of that nature -- including weapons. Typically it involves shorter service life, smaller size (although there are some Really Big machines out there!) and more precision.

the upstream of a pipe is its inlet and the downstream is its outlet

****if your talking about broadband/internet speed*****downstream is taking information from the internet.(downloading) upstream is putting info on the internet uploading

the metal used in building most planes is alumiun as this type of metal as it can expand as the pressure in side the aircraft is greater than the pressure outside the aircraft. it is also the lightest suitable metal although boeing's 787 has been constucted with acompisite material.

Normal flow is 100% of the flow you actually expect. Rated flow is the maximum safety factor times the normal flow.

i.e. for a maximum safety factor of 1.2

Normal flow = 100 gpm

Rated flow = 1.2*100 gpm = 120 gpm

Safety factors are applied to ensure a piece of equipment has some flexibility of operating conditions in its application.

The minimum flow is the minimum safety factor time the normal flow

i.e.

i.e. for a maximum safety factor of 0.5

Normal flow = 100 gpm

Rated flow = 0.5*100 gpm = 50 gpm

If sized properly a pump specified in this way could operate at any point between 50 and 120gpm with no problems.

Tolerances H7 23DIA for hile is +0.021/-0.000 ///MUKI

This will depend on how readily available the materials are. It can usually take a couple of months to complete.